For fans of AMC's addictive, high-quality drama Mad Men, it was when months of plot lines and missed opportunities came together in a single, searing bit of dialogue.

The Scene is likely the biggest reason Moss was nominated for a Best Actress Emmy, sandwiched among boldface names such as Sally Field, Glenn Close, Holly Hunter and Kyra Sedgwick.

Which Scene, you ask? The one in which Peggy Olson tells a colleague their office tryst produced a child she didn't keep. "I could have shamed you into being with me . . . (but) I wanted other things," she informs him with soft brutality.

Calling by cell phone from Los Angeles, Moss said she knows why it worked.

"I think people were just happy to see her talk about anything . . . to reveal any sort of part about herself," she said, laughing. "She's sort of an everyman — like Ernest Borgnine in Marty — the character that's really identifiable. People wanted to see her say just the right thing to just the right person . . . and they felt happy for themselves, in a way, after she did."

• • •

Mad Men inspires fans to pay obsessive attention to tiny details — and rewards them for doing so, thanks to executive producer Matthew Weiner's attention to detail and taste for slow storytelling.

On the surface, Mad Men is a hyper-stylized drama about a '60s-era Madison Avenue advertising firm and the man who serves as its creative soul, Jon Hamm's mysterious, Machiavellian Don Draper.

But the show also examines America at a turning point, with the characters yearning for new roles they can feel are just around the cultural corner.

Mad Men is officially a pop culture phenomenon, with tonight's third season debut heralded by photo spreads in Vanity Fair and Entertainment Weekly magazines, appearances by Hamm on Live With Regis and Kelly and The Tonight Show and an entire fashion line dedicated to the series by superstar clothes designer Michael Kors.

But as much as the industry loves to laud Mad Men — to the tune of 16 Emmy nominations this year, including Moss' — that infatuation hasn't translated to viewership.

Indeed, the show last season averaged about 1.5 million viewers per episode after a debut that drew 2 million, according to Nielsen Media Research. In comparison, the Aug. 6 finale for USA Network's spy drama Burn Notice drew 7.6 million viewers, a record high for the network.

So if this show is so hip and so good, why aren't more people watching it?

"I don't know a lot of people that sit down and watch it (when it airs)," said Moss, noting that some fans seem to prefer watching multiple downloads on iTunes or sitting down with the DVD collection long after a season has aired. "I know I personally don't like watching a show once a week. It drives me crazy."

Moss' point is echoed by Mad Men superfan Deborah Lipp, a writer and Internet marketing guru in New Jersey who joined with sister Roberta in October 2007 to start a blog centered on the show, Basket of Kisses.

Lipp says the show's best quality — slow, detailed storytelling that unfolds over many episodes — also becomes the biggest barrier to new fans.

Is Mad Men too good for its own good?

Lipp doesn't think so. "The renewable reward of the show is part of its appeal; it just keeps getting more interesting the more you watch it," she said. "If you're watching TV because you want to unwind and see a lot of pretty colors, Mad Men is not a good idea. Mad Men is a show to be paid attention to."

• • •

Moss, who lives in New York with fiance and Saturday Night Live veteran Fred Armisen, doesn't pretend to understand what people watch on television.

But she's hopeful this is the year Mad Men draws more viewers than usual. In one story line, Olson must decide whether she can do the things women traditionally do and also blaze a trail as the only female executive at her advertising firm.

We see her emerge as Draper's protege, encouraged and challenged by him even as she mimics his ruthlessness. The question she'll face: How much like Draper does she want to be?

And don't make the mistake of asking her, as fans did early on, whether the naive, awkward Olson is very smart. "I would ask people, 'How smart were you at 20 years old?' " said Moss, who gained early fame playing the president's daughter on NBC's The West Wing. "I think people forget she's 20 years old in 1960. I think she's a good person and doesn't understand why everyone else isn't a good person, too."

This season opens in typical Mad Men fashion, with moves you would never expect. We see little of Moss' Olson and instead watch Draper on a business trip where he doesn't exactly act like a guy whose wife nearly divorced him for infidelity.

If that wasn't enough, here are a few more reasons why Mad Men isn't a Burn Notice-sized hit:

• It airs on AMC, a cable channel many viewers still see as a home for old movies.

• It demands a lot from viewers, with characters who react in unexpected ways.

• It's a period piece about media, which appeals to media and showbiz people but may seem inaccessible to others.

Of course, some experts see this as a grand show business tradition. "I don't think thirtysomething got anywhere past thirtysomething in the ratings, but we all use that phrase now," said Bob Thompson, director of the Bleier Center for Television and Popular Culture at Syracuse University. "Sometimes the stuff that is most celebrated doesn't translate into actual consumption."

But superfan Lipp is also convinced this could be Mad Men's year to draw viewers commensurate with its cultural impact. "It's finally rolled over . . . there's fashion spreads in House Beautiful and political commentary based on the show," she said. "Besides, there's always going to be people like me who could care less what's happening on The Mentalist or CSI."

Eric Deggans can be reached at deggans@sptimes.com or (727) 893-8521. See his blog at blogs.tampabay.com/media.

REVIEW

Mad Men

The drama returns for its third season at 10 tonight on AMC. Rating: TV-14. Grade: A+.

FAST FACTS

Clocking in for Season 3 of 'Mad Men'

Where does everybody stand in tonight's episode?

Don Draper (Jon Hamm) Sent to Baltimore on a business trip while downsizing by the firm's new British owners roils the workplace.

Betty Draper (January Jones) Struggling with a new pregnancy, she's relearning to trust her husband after an indiscretion of her own.

Pete Campbell (Vincent Kartheiser) Always snatching defeat from the jaws of victory, he gets a promotion that isn't nearly as good as it seems.

Peggy Olson (Elisabeth Moss) Her advertising copywriting job makes her too powerful to pal with other women in the office, but too feminine to bond with the guys.